U.S. patent number 6,599,315 [Application Number 09/991,391] was granted by the patent office on 2003-07-29 for stent and stent delivery assembly and method of use.
This patent grant is currently assigned to Advanced Cardiovascular Systems, Inc.. Invention is credited to W. Stan Wilson.
United States Patent |
6,599,315 |
Wilson |
July 29, 2003 |
Stent and stent delivery assembly and method of use
Abstract
A stent delivery catheter assembly for delivering and implanting
a stent at or near an area of septal perforators includes a
torquing member which, in cooperation with a tracking guide wire
and a positioning guide wire, facilitates torquing and rotation of
the catheter and hence the position of the stent mounted thereon to
accurately position and implant the stent at or near the area of
septal perforators. The stent of the present invention has an
elongated side aperture which is designed to be implanted next to
the area of septal perforators to prevent covering of the orifices
of the septal perforators.
Inventors: |
Wilson; W. Stan (Missoula,
MT) |
Assignee: |
Advanced Cardiovascular Systems,
Inc. (Santa Clara, CA)
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Family
ID: |
23834570 |
Appl.
No.: |
09/991,391 |
Filed: |
November 20, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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461946 |
Dec 15, 1999 |
6361555 |
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Current U.S.
Class: |
623/1.11;
606/108 |
Current CPC
Class: |
A61F
2/856 (20130101); A61F 2/954 (20130101); A61F
2/958 (20130101); A61F 2/91 (20130101) |
Current International
Class: |
A61F
2/06 (20060101); A61F 002/06 (); A61M 029/00 () |
Field of
Search: |
;623/1.11,1.15
;606/108,194 |
References Cited
[Referenced By]
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Other References
Lawrence, David D., Jr., M.D., et al., Percutaneous Endovascular
Graft: Experimental Evaluation, Radiology, vol. 163, No. 2, pp.
357-360 (1987). .
Yoshioka, Tetsuya, et a., Self-Expanding Endovascular Graft: An
Experimental Study in Dogs, Radiology, vol. 170, pp. 1033-1037
(1989). .
Parodi, J.C., M.D., et al., Transfemoral Intraluminal Graft
Implantation for Abdominal Aortic Aneuyrsms, Annals of Vascular
Surgery, vol. 5, No. 6, pp. 491-499 (1991). .
Mirich, David, M.D., Percutaneously Placed Endovascular Grafts for
Aortic Aneurysms: Feasibility Study, Radiology, vol. 170, No. 3,
Part 2, pp. 1033-1037 (1989). .
Chuter, Timothy A.M., BM, BS, et al., Transfemoral Endovascular
Aortic Graft Placement, Journal of Vascular Surgery, pp. 185-196
(Aug., 1993). .
Bard XT Catina Bifurcate Stent (Brochure) (Undated)..
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Primary Examiner: Willse; David H.
Assistant Examiner: Jackson; Suzette J.
Attorney, Agent or Firm: Fulwider Patton Lee & Utecht,
LLP
Parent Case Text
This application is a divisional of U.S. application Ser. No.
09/461,946 filed Dec. 15, 1999, which is now U.S. Pat. No.
6,361,555.
Claims
What is claimed is:
1. A method for treating a vessel with septal perforators,
comprising: providing an elongated catheter having an expandable
member positioned thereon, tracking guide wire disposed within a
tracking guide wire lumen and a positioning guide wire disposed
within a positioning guide wire lumen, said positioning guide wire
lumen having a distal opening formed in said catheter adjacent said
expandable member; providing a torquing member attached to both
said tracking guide wire lumen and said positioning guide wire
lumen; positioning an expandable stent having a side aperture on
said catheter so as envelop said expandable member and such that
said distal opening of said positioning guide wire is aligned with
a portion of said aperture; advancing said catheter through a
vessel having septal perforators along said tracking guide wire to
a position wherein said stent is substantially longitudinally
aligned and wherein said positioning guide wire lumen opening is
generally radially aligned with said septal perforators; advancing
said positioning guide wire so as to emerge from said distal
opening in said positioning guide wire and enter one of said septal
perforators; further advancing said catheter in a distal direction
so as to cause said catheter and stent to rotate into substantial
alignment with said septal perforators by torque created by the
positioning guide wire and tracking guide wire which is transferred
to the catheter by said torquing member; and expanding said
expandable member to expand said stent.
2. The method of claim 1, wherein said expandable stent has
multiple side apertures formed therein.
3. The method of claim 2, wherein each of said apertures is aligned
with one of said septal perforators.
4. The method of claim 1, wherein said side aperture is
elongated.
5. The method of claim 4, wherein said aperture is aligned with a
plurality of said septal perforators.
6. The method of claim 1, wherein said aperture encompasses about
60 degrees of said stent's circumference.
Description
BACKGROUND OF THE INVENTION
The invention relates to stent deployment assemblies for use at a
bifurcation and, more particularly, a catheter assembly for
implanting one or more stents for treating septal perforation, and
a method and apparatus for delivery and implantation.
Stents conventionally repair blood vessels that are diseased and
are generally hollow and cylindrical in shape and have terminal
ends that are generally perpendicular to their longitudinal axes.
In use, the conventional stent is positioned at the diseased area
of a vessel and, after placement, the stent provides an
unobstructed pathway for blood flow.
Repair of vessels that are diseased at a bifurcation is
particularly challenging since the stent must overlay the entire
diseased area at the bifurcation, yet not itself compromise blood
flow. Therefore, the stent must, without compromising blood flow,
overlay the entire circumference of the ostium to a diseased
portion and extend to a point within and beyond the diseased
portion. Where the stent does not overlay the entire circumference
of the ostium to the diseased portion, the stent fails to
completely repair the bifurcated vessel. Where the stent overlays
the entire circumference of the ostium to the diseased portion, yet
extends into the junction comprising the bifurcation, the diseased
area is repaired, but blood flow may be compromised in other
portions of the bifurcation. Unopposed stent elements may promote
lumen compromise during neointimalization and healing, producing
restenosis and requiring further procedures. Moreover, by extending
into the junction comprising the bifurcation, the stent may block
access to portions of the bifurcated vessel that require
performance of further interventional procedures. Similar problems
are encountered when vessels are diseased at their angled origin
from the aorta as in the ostium of a right coronary or a vein
graft. In this circumstance, a stent overlying the entire
circumference of the ostium extends back into the aorta, creating
problems, including those for repeat catheter access to the vessel
involved in further interventional procedures.
Conventional stents are designed to repair areas of blood vessels
that are removed from bifurcations and, since a conventional stent
generally terminates at right angles to its longitudinal axis, the
use of conventional stents in the region of a vessel bifurcation
may result in blocking blood flow of a side branch or fail to
repair the bifurcation to the fullest extent necessary. The
conventional stent might be placed so that a portion of the stent
extends into the pathway of blood flow to a side branch of the
bifurcation or extend so far as to completely cover the path of
blood flow in a side branch. The conventional stent might
alternatively be placed proximal to, but not entirely overlaying,
the circumference of the ostium to the diseased portion. Such a
position of the conventional stent results in a bifurcation that is
not completely repaired. The only conceivable situation that the
conventional stent, having right-angled terminal ends, could be
placed where the entire circumference of the ostium is repaired
without compromising blood flow, is where the bifurcation is formed
of right angles. In such scenarios, extremely precise positioning
of the conventional stent is required. This extremely precise
positioning of the conventional stent may result with the
right-angled terminal ends of the conventional stent overlying the
entire circumference of the ostium to the diseased portion without
extending into a side branch, thereby completely repairing the
right-angled bifurcation.
To circumvent or overcome the problems and limitations associated
with conventional stents in the context of repairing diseased
bifurcated vessels, a stent that consistently overlays the entire
circumference of the ostium to a diseased portion, yet does not
extend into the junction comprising the bifurcation, may be
employed. Such a stent would have the advantage of completely
repairing the vessel at the bifurcation without obstructing blood
flow in other portions of the bifurcation. In addition, such a
stent would allow access to all portions of the bifurcated vessel
should further interventional treatment be necessary. In a
situation involving disease in the origin of an angulated
aorto-ostial vessel, such a stent would have the advantage of
completely repairing the vessel origin without protruding into the
aorta or complicating repeat access.
In addition to the problems encountered by using the prior art
stents to treat bifurcations, the delivery platform for implanting
such stents has presented numerous problems. For example, a
conventional stent is implanted in the main vessel so that a
portion of the stent is across the side branch, so that stenting of
the side branch must occur through the main-vessel stent struts. In
this method, commonly referred to in the art as the "monoclonal
antibody" approach, the main-vessel stent struts must be spread
apart to form an opening to the side-branch vessel and then a
catheter with a stent is delivered through the opening. The cell to
be spread apart must be randomly and blindly selected by recrossing
the deployed stent with a wire. The drawback with this approach is
there is no way to determine or guarantee that the main-vessel
stent struts are properly oriented with respect to the side branch
or that the appropriate cell has been selected by the wire for
dilatation. The aperture created often does not provide a clear
opening and creates a major distortion in the surrounding stent
struts. The drawback with this approach is that there is no way to
tell if the main-vessel stent struts have been properly oriented
and spread apart to provide a clear opening for stenting the
side-branch vessel.
In another prior art method for treating bifurcated vessels,
commonly referred to as the "Culotte technique," the side-branch
vessel is first stented so that the stent protrudes into the main
vessel. A dilatation is then performed in the main vessel to open
and stretch the stent struts extending across the lumen from the
side-branch vessel. Thereafter, the main-vessel stent is implanted
so that its proximal end overlaps with the side-branch vessel. One
of the drawbacks of this approach is that the orientation of the
stent elements protruding from the side-branch vessel into the main
vessel is completely random. Furthermore, the deployed stent must
be recrossed with a wire blindly and arbitrarily selecting a
particular stent cell. When dilating the main vessel stretching the
stent struts is therefore random, leaving the possibility of
restricted access, incomplete lumen dilatation, and major stent
distortion.
In another prior art device and method of implanting stents, a "T"
stern procedure includes implanting a stent in the side-branch
ostium of the bifurcation followed by stenting the main vessel
across the side-branch ostium. In another prior art procedure,
known as "kissing" stents, a stent is implanted in the main vessel
with a side-branch stent partially extending into the main vessel
creating a double-barreled lumen of the two stents in the main
vessel distal to the bifurcation. Another prior art approach
includes a so-called "trouser legs and seat" approach, which
includes implanting three stents, one stent in the side-branch
vessel, a second stent in a distal portion of the main vessel, and
a third stent, or a proximal stent, in the main vessel just
proximal to the bifurcation.
All of the foregoing stent deployment assemblies suffer from the
same problems and limitations. Typically, there is uncovered
intimal surface segments on the main vessel and side-branch vessels
between the stented segments. An uncovered flap or fold in the
intima or plaque will invite a "snowplow" effect, representing a
substantial risk for subacute thrombosis, and the increased risk of
the development of restenosis. Further, where portions of the stent
are left unopposed within the lumen, the risk for subacute
thrombosis or the development of restenosis again is increased. The
prior art stents and delivery assemblies for treating bifurcations
are difficult to use, making successful placement nearly
impossible. Further, even where placement has been successful, the
side-branch vessel can be "jailed" or covered so that there is
impaired access to the stented area for subsequent
intervention.
In addition to problems encountered in treating disease involving
bifurcations for vessel origins, difficulty is also encountered in
treating disease confined to a vessel segment but extending very
close to a distal branch point or bifurcation which is not diseased
and does not require treatment. In such circumstances, very precise
placement of a stent covering the distal segment, but not extending
into the ostium of the distal side-branch, may be difficult or
impossible.
Problems analogous to the problems described above occur when
attempting to treat an area in a vessel surrounding septal
perforators. Septal perforators are branch vessels "perforating"
into the interventricular septum as branch vessels of either the
left anterior descending or posterior descending coronary arteries.
Septal perforators are usually multiple and exit in linear fashion
from the septal surface of these main vessels as multiple
bifurcations. Using a conventional stent in these epicardial
vessels often results in plaque shifting and "snowplow" obstruction
of multiple septal perforators within the stented segment. This
compromises blood flow through the septal perforators. The present
invention solves these problems related to treating an area
surrounding septal perforators as will be shown.
As used herein, the terms "proximal," "proximally," and "proximal
direction" when used with respect to the invention are intended to
mean moving away from or out of the patient, and the terms
"distal," "distally," and "distal direction" when used with respect
to the invention are intended to mean moving toward or into the
patient. These definitions will apply with reference to apparatus,
such as catheters, guide wires, stents, the like.
SUMMARY OF THE INVENTION
The invention provides for an improved stent design and stent
delivery assembly for repairing an area in an artery having septal
perforations, without compromising blood flow in other portions of
the vessels, thereby allowing access to all portions of the vessels
should further interventional treatment be necessary. The stent
delivery assembly of the invention has the novel feature of
containing, in addition to a tracking guide wire, a positioning
guide wire and torquing member that affect rotation and precise
positioning of the assembly for deployment of the stent.
In one aspect of the invention, there is provided a longitudinally
flexible stent for implanting in a body lumen and expandable from a
contracted condition to an expanded condition. The stent includes a
cylindrical member having an elongated side aperture. The stent can
be used to treat areas proximate to septal perforators without
occluding the septal perforators.
In another aspect of the invention, there is provided a stent
delivery catheter assembly that includes an elongated catheter. The
catheter has an inflation lumen, a tracking guide wire lumen, and a
positioning guide wire lumen. An expandable member is positioned at
a distal end of the catheter and is in fluid communication with the
inflation lumen. A stent is mounted on the expandable member, the
stent being longitudinally flexible and for implanting in a body
lumen and expandable from a contracted condition to an expanded
condition. The stent includes an elongated side aperture such that
the stent can be used to treat areas proximate septal perforators
without occluding the septal perforators. A torquing member is
attached to the tracking guide wire lumen and positioning guide
wire lumen so that as the catheter is positioned in a body lumen,
the torquing member assists in properly orienting the stent in the
lumen.
In another aspect, there is provided a method of stenting a vessel
having septal perforation. The method includes the steps of
providing a tracking guide wire and tracking guide wire lumen;
providing a positioning guide wire and positioning guide wire
lumen; providing a torquing member; torquing the positioning guide
wire relative to the tracking guide wire with the assistance of the
torquing member; and rotating a stent into a desired position
within the vessel.
Other features and advantages of the present invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a bifurcation in which a prior art
"T" stent is in a side-branch ostium followed by the stenting of
the main vessel across the branch ostium.
FIG. 2 is an elevational view of a bifurcation in which "touching"
prior art stents are depicted in which one stent is implanted in
the side branch, a second stent implanted in a proximal portion of
the main vessel next to the branch stent, with interrupted
placement of a third stent implanted more distally in the main
vessel.
FIG. 3 is an elevational view of a bifurcation depicting "kissing"
stents where a portion of one stent is implanted in both the
side-branch and the main vessel and adjacent to a second stent
implanted in the main vessel creating a double-barreled lumen in
the main vessel proximal to the bifurcation.
FIG. 4 is an elevational view of a prior art "trouser legs and
seat" stenting approach depicting one stent implanted in the
side-branch vessel, a second stent implanted in a proximal portion
of the main vessel, and a close deployment of a third stent distal
to the bifurcation leaving a small gap between the three stents of
an uncovered lumenal area.
FIG. 5A is an elevational view of a bifurcation in which a prior
art stent is implanted in the side-branch vessel.
FIG. 5B is an elevational view of a bifurcation in which a prior
art stent is implanted in the side-branch vessel, with the proximal
end of the stent extending into the main vessel.
FIG. 6 is an elevational view of an area of a vessel having septal
perforators, in which a prior art stent is implanted in the vessel
with the stent occluding some of the septal perforators.
FIG. 7A is a perspective view of a stent of the present invention
depicting the elongated side aperture.
FIG. 7B is a plan view of the stent of FIG. 7A.
FIG. 8 is an elevational view of the stent of FIG. 7 depicting the
elongated side aperture.
FIG. 9 is an elevational view of the catheter distal section
depicting the two guide wire delivery system.
FIG. 10 is a longitudinal cross-sectional view of the catheter
distal section of FIG. 9 depicting aspects of the invention.
FIG. 11 is a transverse cross-sectional view of the catheter
depicting the guide wire lumens and the inflation lumen.
FIG. 12 is a transverse cross-sectional view of the catheter distal
section depicting the torquing member and expandable member.
FIG. 13 is a partial elevational view depicting the torquing member
in phantom lines.
FIG. 14 is a partial elevational view depicting the exit port for
the positioning guide wire.
FIG. 15 is a partial elevational view depicting a slit associated
with the exit port shown in FIG. 14.
FIG. 16 is a longitudinal cross-sectional view of the catheter
distal section and torquing member.
FIG. 17 is a longitudinal cross-sectional view of the catheter
distal section and the torquing member.
FIG. 18 is an elevational view of the catheter of FIG. 9 at a
target site before implantation of a stent.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in the exemplary drawings wherein like reference numerals
indicate like or corresponding elements among the figures, the
present invention includes an assembly and method for treating
septal perforators.
Prior art attempts at implanting intravascular stents in a
bifurcation have proved less than satisfactory. For example, FIGS.
1-4 depict prior art devices which include multiple stents being
implanted in both the main vessel and a side-branch vessel. In FIG.
1, a prior art "T" stent is implanted such that a first stent is
implanted in the side branch near the ostium of the bifurcation,
and a second stent is implanted in the main vessel, across the
side-branch ostium. With this approach, portions of the side-branch
vessel are left uncovered, and blood flow to the side-branch vessel
must necessarily pass through the main-vessel stent, causing
possible obstructions or thrombosis.
Referring to FIG. 2, three prior art stents are required to stent
the bifurcation. In FIG. 3, the prior art method includes
implanting two stents side by side, such that one stent extends
into the side-branch vessel and the main vessel, and the second
stent is implanted in the main vessel. This results in a
double-barreled lumen which can present problems such as
thrombosis, and turbulence in blood flow. Referring to the FIG. 4
prior art device, a first stent is implanted in the side-branch
vessel, a second stent is implanted in a proximal portion of the
main vessel, and a third stent is implanted distal to the
bifurcation, thereby leaving a small gap between the stents and an
uncovered lumenal area.
Referring to FIGS. 5A and 5B, a prior art stent is configured for
deployment in side-branch vessel 5. In treating side-branch vessel
5, if a prior art stent is used, a condition as depicted will
occur. That is, a stent deployed in side-branch vessel 5 will leave
a portion of the side-branch vessel exposed, or as depicted in 5B,
a portion of the stent will extend into main vessel 6.
Turning to FIG. 6, as mentioned above, similar problems occur when
using conventional methods to treat an area in vessel 6 proximate
to septal perforators 7. A segment of left anterior descending (or
posterior descending) often contains ostia of a sequence of several
septal perforators arranged in a linear configuration. Deployment
of a conventional stent in this commonly diseased location
frequently results in snowplow compromise of the origins, or
orifices 8, of these septal perforators. Additionally, a
conventional stent can jail orifices 8 leading from main vessel
branch 6 to the septal perforators. Furthermore, disease can be
snowplowed into the orifices and healthy portions of the vessels.
Thus, snowplow obstructions 4 are created in orifices 8,
compromising blood flow. While a side aperture stent could be
selected to prevent snowplowing in a single septal, it may be more
optimal to utilize another stent of a specific design. The present
invention solves the problems associated with treating septal
perforation.
In keeping with the invention, as depicted in FIGS. 7A-8, "septal
saving" stent 20 is configured for deployment in main vessel 6.
Main vessel stent 20 includes cylindrical member 21 having distal
end 22 and proximal end 23. Main vessel stent 20 includes outer
wall surface 24 which extends between distal end 22 and proximal
end 23 and incorporates elongated side aperture 25 on outer wall
surface 24. Aperture 25 is configured so that, upon expansion, it
is wide enough to cover orifices 8 and long enough to accommodate a
desired number of septal perforators. In one embodiment, the
elongated side aperture can encompass about 60 degrees of the 360
degrees radius, in which only very limited stent elements, if any,
are present to permit radial continuity. However, it is
contemplated that greater or lesser ranges of radius can be
encompassed. When main vessel stent 20 is implanted and expanded
into contact with main vessel 6, aperture 25 is aligned with
orifices 8, thereby providing an unrestricted blood flow path from
the main vessel through the septal perforators.
Stent 20 can be formed from any of a number of materials including,
but not limited to, stainless steel alloys, nickel-titanium alloys
(the NiTi can be either shape memory or pseudoelastic), tantalum,
tungsten, or any number of polymer materials. Such materials of
manufacture are known in the art. Further, the stent can have
virtually any pattern known to prior art stents. In one
configuration, the stent is formed from a stainless steel material
and has a plurality of cylindrical elements connected by connecting
members, wherein the cylindrical elements have an undulating or
serpentine pattern. Such a stent is disclosed in U.S. Pat. No.
5,514,154 and is manufactured and sold by Advanced Cardiovascular
Systems, Inc., Santa Clara, Calif. The stent is sold under the
trade name MultiLink.RTM. Stent. Such stents can be modified to
include the novel features of stent 20.
Stent 20 preferably is a balloon-expandable stent that is mounted
on a balloon portion of a catheter and crimped tightly onto the
balloon to provide a low profile delivery diameter. After the
catheter is positioned so that the stent and the balloon portion of
the catheter are positioned in the main vessel, the balloon is
expanded, thereby expanding the stent into contact with the vessel.
Thereafter, the balloon is deflated and the balloon and catheter
are withdrawn from the vessel, leaving the stent implanted. The
stent 20 could be made to be either balloon expandable or
self-expanding.
In keeping with the invention, as shown in FIGS. 9-17, a two guide
wire delivery catheter assembly 120 is configured to provide
maximum torque so that the catheter can be properly positioned in a
bifurcated vessel to deliver and implant stent 20. Referring now to
FIGS. 9 and 10, elongated catheter 121 is adapted to deliver and
implant a stent and it includes proximal end 121a and distal end
121b. The catheter further is defined by distal section 123 which
has an inflation lumen 124, a tracking guide wire lumen 125 and a
positioning guide wire lumen 126 extending therethrough. An
expandable member 128 is positioned at distal section 123 and is in
fluid communication with inflation lumen 124. It is contemplated
that the tracking guide wire lumen and positioning guide wire lumen
could extend along an outer surface of the expandable member. The
expandable member preferably extends from proximal end 128a to
distal end 128b, however it is preferred that the inflation lumen
not run all the way through the expandable member so that the
expandable member is lumenless. A lumenless expandable member
provides for a smaller profile.
The lumenless expandable member 128 is positioned at a distal end
of the catheter 121 and is in fluid communication with the
inflation lumen 124. The expandable member distal end 128b is
attached to the outer surface of catheter tracking wire lumen
distal end 125b. The expandable member is generally a balloon
similar to that used in angioplasty procedures. The expandable
member is typically non-distensible, having a first compressed
diameter for delivery through a vascular system and a second
expanded diameter for implanting a stent.
The present invention provides for a torquing member to assist in
torquing the catheter to optimally position the guide wires and
properly orient the stent in the vasculature. A torquing member
140, as shown in FIG. 17, is attached to and aligned with tracking
wire lumen 125 and positioning guide wire lumen 126. The torquing
member is comprised of first port 140a and second port 140b. As
depicted in FIG. 17, the torquing member comprises tracking wire
lumen 141 and positioning guide wire lumen 142. The torquing member
positioning guide wire lumen 142 has a proximal end 142a and a
distal end 142b while torquing member tracking guide wire lumen 141
has a proximal end 141a and a distal end 141b. The torquing member
tracking guide wire lumen proximal end 141a is aligned with the
catheter tracking guide wire lumen 125. The torquing member
positioning guide wire lumen proximal end 142a is aligned with the
catheter positioning guide wire lumen 126. Thus, there is a
substantially continuous guide wire lumen for each of the tracking
and positioning guide wire lumens that extend through at least a
portion of the catheter, through the torquing member, and the
tracking guide wire lumen extends distally of the torquing member.
The tracking guide wire lumen 125 slidably receives tracking guide
wire 150 and positioning guide wire lumen 126 slidably receives
positioning guide wire 151. The tracking guide wire slidably
extends through the catheter guide wire tracking lumen and through
the torquing member guide wire lumen. The positioning guide wire
slidably extends through the catheter positioning guide wire lumen
and through the torquing member positioning guide wire lumen where
it exits into a vessel. The guide wires 150, 151 preferably are
stiff wires each having a diameter of 0.014 inch, but can have
different diameters and degrees of stiffness as required for a
particular application. A particularly suitable guide wire can
include those manufactured and sold under the tradenames Sport.RTM.
and Ironman.RTM., manufactured by Advanced Cardiovascular Systems,
Inc., Santa Clara, Calif.
In keeping with the invention, torquing member 140 further
comprises ramp 143 positioned in the positioning guide wire lumen
142. The ramp is positioned in the torquing member and assists the
positioning guide wire in advancing through and exiting the
catheter. The ramp 143 is sloped and begins a gradual upward slope
at the torquing member first port 140a and ends slightly proximal
to the torquing member second port 140b. The ramp is distal to the
torquing member first port 140a and proximal to the torquing member
second port 140b. The ramp ends at opening (or exit port) 145 just
proximal to the torquing member second port 140b. The gradual
upward slope of the ramp will facilitate the advancement of
positioning guide wire 151 so that the guide wire slides up the
ramp as it is advanced and it exits the catheter through opening
145 at second port 140b.
As shown in FIG. 15, the torquing member positioning guide wire
lumen 142 preferably has slit 144 in catheter wall 146 located on
the side of catheter 121 opposite of opening 145, and is positioned
proximal to opening 145. As the positioning guide wire advances
through positioning guide wire lumen 126 and slides along ramp 143,
it may have a tendency to bend slightly as it encounters frictional
resistance along the gradual slope of the ramp. In order to relieve
the bending moments in the wire, slit 144 allows the wire to flex
into the slit thereby providing a more gradual bend in the
positioning guide wire.
The torquing member 140 preferably is formed from a rigid material
made from plastic or metal. As shown in FIG. 10, catheter tracking
guide wire lumen 125 extends from the torquing member forming a
continuous lumen proximal to the torquing member and through it to
the catheter distal end.
A stent 20, as shown in FIG. 9, is mounted on the stent delivery
catheter assembly 120. The stent has aperture 25 so that the stent
does not cover septal perforators in a patient or opening 145 where
the positioning guide wire exits. Preferably the stent is mounted
on expandable member 128 so that the torquing member is
exposed.
The catheter distal section 123 extends from proximal end 123a to
distal end 123b. The torquing member 140 can be positioned at any
point along the catheter distal section as long as torquing member
140 corresponds with aperture 25 of stent 20.
While the torquing member 140 embodiment has been described in
connection with delivery of a stent at septal perforators, its
application is broader and can be used to position other devices
such as drug delivery means, atherectomy devices, radioactive
materials, and the like.
In further keeping with the invention, as depicted in FIG. 18,
stent 20 is mounted on assembly 120 and implanted in vessel 6. The
method of achieving stent implantation is as follows.
In keeping with one method of the invention, stent 20 is tightly
crimped onto catheter assembly 120 including expandable member 128
for low-profile delivery through the vasculature system. It is
particularly critical that aperture 25 of the stent be aligned with
opening 145. The distal end of tracking guide wire 150 is advanced
into main vessel 6 and distal to the target area, with the proximal
end of the tracking guide wire remaining outside the patient. The
distal section 123 of the catheter is then advanced, preferably
with the use of a guiding catheter (not shown), along the tracking
wire until the stent is properly longitudinally positioned at the
target area. Up to this point, positioning guide wire 151 resides
in positioning guide wire lumen 126 so that the distal end of the
positioning wire preferably is near opening 145. This method of
delivery prevents the two guide wires from wrapping around each
other, the positioning wire being protected by the catheter
assembly during delivery.
The distal end of positioning guide wire 151 is then advanced by
having the physician push the proximal end from outside the body.
The distal end of the integrated positioning guide wire travels
through positioning guide wire lumen 126, up ramp 143 whereby the
wire is forced to move radially outwardly, and out of opening 145.
Preferably, opening 145 is already somewhat aligned with orifice 8
of a septal perforator 7. If not, then some rotation and
longitudinal displacement of assembly 120 may be needed in order to
advance the positioning guide wire into an orifice of a septal
perforator.
After positioning guide wire 151 is advanced into a septal
perforator 7, the physician further advances assembly 120 in the
distal direction. Due to the assistance of torquing member 140,
this action causes the positioning guide wire to push against a
wall of the septal perforator, thus creating a torquing force in
the positioning guide wire relative to tracking guide wire 150.
This torquing force acts to rotate stent 20 such that aperture 25
comes into alignment with orifice 8.
Now expandable member 128 is expanded by known methods, thereby
expanding stent 20 into apposition with vessel 6, and thereby
implanting the stent in the vessel. As shown in FIG. 18, support
struts 129 can be included as part of the stent on each side of
opening 145. Thereafter, the expandable member is deflated and
catheter assembly 120 is withdrawn from the patient's vasculature.
The catheter assembly can be designed so that both tracking guide
wire 150 and positioning guide wire 151 can be left in their
respective vessels should sequential or simultaneous high pressure
balloon inflation be required in vessel 6 in order to complete the
stenting procedure. In other words, the wires can be unzipped
through slits (not shown) from the catheter thereby allowing the
wires to act as a rapid exchange wires.
While the invention herein has been illustrated and described in
terms of an apparatus and method for treating septal perforation,
it will be apparent to those skilled in the art that the stents and
delivery systems herein can be used in the coronary arteries,
veins, and other arteries throughout the patient's vascular system.
Certain dimensions and materials of manufacture have been described
herein, and can be modified without departing from the spirit and
scope of the invention.
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